Ireland’s long-term sovereign credit rating was cut one step to AA- from AA by Standard & Poor’s, which cited the projected cost of supporting the nation’s financial sector.

“The negative outlook reflects our view that a further downgrade is possible if the fiscal cost of supporting the banking sector rises further, or if other adverse economic developments weaken the government’s ability to meet its medium- term fiscal objectives,” S&P said today in a statement.

S&P said its new projections suggest that Ireland’s net general government debt will rise toward 113 percent of gross domestic product in 2012. That’s more than 1.5 times the median for the average of euro zone sovereign nations, and “well above” the debt burdens the New York-based firm said it projects for similarly rated countries in the region such as Belgium at 98 percent and Spain at 65 percent.